What can you say about a calcium atom by looking at the symbol 44/20 ca?
a. a calcium atom has 44 neutron s and 20 electrons.
b. a calcium atom has 20 protons and 24 electrons.
c. a calcium atom has 64 protons and 20 neutrons.
d. a calcium atom has 20 protons and 24 neutrons.
e. a calcium atom has 20 protons and 44 neutrons.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o